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\ TAPPET Filed Aug. 5, 1960 2 Sheets-Sheet 1 INVENTOR.

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March 1964 c. VQORHIES 3,124,114

TAPPET Filed Aug. 5, 1960 2 Sheets-Sheet 2 INVENTOR.

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United States Patent 3,124,114 TAPPET Carl Voorhies, Park Ridge, Ill. Filed Aug. 5, 1960, Ser. No. 47,665 13 Claims. (Cl. 123-90) This invention relates to a hydraulic tappet and it has for one object to provide a tappet so constructed that oil is fed or moves through the tappet to the engine push rod and is available for the lubrication of various parts of the valve gear hydraulic tappets are frequently called in the trade valve lifters, tappets or lash adjusters. These terms may be used interchangeably.

A hydraulic tappet generally includes a cylinder member and a plunger member reciprocating within it. A reservoir space for oil is provided within the tappet and it is one object of this invention to provide a passage to the push rod which does not have direct access to this reservoir or supply chamber but will provide a controlled amount of oil to the push rod.

When hydraulic valve lifters, lash adjusters or tappets are used in internal combustion engines there has been difficulty in the past due to oil leakage from the supply chamber or reservoir space in the tappet, and this is most likely to occur when the engine is not in operation. When it does occur it will cause long continued starting noise after the engine is again started. This leakage is especially likely to occur where the axis of the tappet is in a horizontal or nearly horizontal position. It is an object of this invention to prevent such leakage and to construct the tappet to serve the purpose of lubricating parts of the valve gear while inhibiting or very largely reducing the chance of oil leakage from the supply chamber or reservoir space.

Other objects will appear from time to time throughout the specification and claims.

The invention is illustrated more or less diagrammatic ally in the accompanying drawings wherein:

FIG. 1 is a longitudinal section on an enlarged scale showing a tappet of this invention;

FIG. 2 is a side elevation with parts in section and parts broken away, showing a modification of the plunger of the tappet;

FIG. 3 is a fragmentary View of the end of a further modification of the plunger with parts in elevation and parts in section;

FIG. 4 is a longitudinal section of the tappet on an enlarged scale showing the tappet in one form.

Like parts are designated by like characters throughout the specification and drawings.

1 is the barrel or cylinder of the tappet of this invention. It has a closed end 2 and an external groove 3. The tappet barrel or cylinder is also provided with an internal groove 4. Adjacent its upper end the tappet is provided with a holding groove 5 within which a spring retainer 6 is seated, as shown generally in FIG. 1.

Since the tappet is generally used in an internal combustion engine, it is shown in that relationship in FIG. 1 in which 7 is a cam shaft and 8 is the cam which contacts the closed end 2 of the tappet barrel.

The tappet plunger in the form here shown is a single unitary member. It is mounted within the barrel or cylinder of the tappet and it includes an outer portion or end 9 within which is formed a push rod receiving portion having a depression or socket 10. Around the outside of the portion 9 is formed an oil collecting means comprising a groove 11. A passage 12 leads from the bottom of the socket portion and by means of a passage 13 is in communication with the groove 11.

14 defines the main hollow portion of the plunger within which is formed the cavity 15 which is closed at its upper end by the portion 9 of the plunger. The

cavity 15 is open at its lower end as at 16. About the exterior of the plunger, in the form shown in FIGS. 1 and 2, is a reservoir groove 17 which provides an oil reservoir space which communicates with the cavity 15 by means of the passage or opening 18.

The lower open end of the cavity 15 may be closed by a valve 19. As shown this is a relatively flat valve. It is positioned to be seated against the bottom of the plunger and to close the opening when so seated. The valve 19 is held within a retainer 20 which may be a relatively light or sheet metal cage fixed upon the re duced end 19 of the plunger. A spring 21 is positioned within the retainer 20 and bears against a suitable portion of that retainer and against the valve 19. The spring 21 as shown is in the form of a bent or curved washer. It is biased to hold the valve 19 seated against the end of the plunger to close the open end 16. A compression space is provided between the inner end of the plunger and the closed end 2 of the cylinder.

A spring 22 is provided within the barrel and bearing against the retainer flange 23. This flange is seated against the shoulder 24 of the plunger. The spring 22 is biased to move the plunger outwardly away from the closed end 2 of the barrel.

In the modification shown in FIG. 2 instead of the groove 11 there is provided about the exterior of the portion 9 a band or area of knurling 25. The knurling 25 is of such size, shape and depth that it comprises a. continuous passage or open space about the plunger and is in that sense, so far as the movement of liquid about it is concerned, the equivalent of the groove 11.

In the modification of FIG. 3 the area of knurling 25 which appears in FIG. 2 is retained. Instead of the reservoir groove 17, as shown in FIG. 1, there may be substituted a substantial or relatively wide zone of knurling 29. Thus the groove 11 of the earlier figure is eliminated from the form of FIG. 3 and the general equivalent zone or band of knurling 25 is used and it is this band with which the passage 13 or 26 is in communication. The band of knurling 29, which is substantially wider than that shown at 25, takes the place of the reservoir groove 17 and since a great deal of free volume or free space is provided by the knurling 29, this area acts as a reservoir for oil in the same way in which the open groove 17 acts as a reservoir. The zones 25 and 29 of knurling, as shown in FIG. 3, are separated by an unknurled and ungrooved band or area 39. If desired the zones of knurling 25 and 29 may be made continuous. In that case the unknurled area 30 would be eliminated and the knurling or grooving would be continuous from the top of 25 to the bottom of 29 and would serve the purpose of the grooves 11 and 17.

I claim:

1. For use in a hydraulic lash adjusted, a hollow unitary plunger, said plunger shaped to provide an external reservoir space and a separated external collecting space, each such space comprising an area of knurling, a passage from said reservoir space to the interior of said plunger, a push rod seat on said plunger, and a passage from said seat to said collecting space.

2. For use in a hydraulic lash adjuster, a hollow plunger open at one end and having a push rod receiving seat at its other end, said plunger shaped on its exterior to provide a reservoir space comprising an area of knurling and having a passage from said reservoir space to its interior, said plunger also being provided with a lubricantcollecting space on its exterior, said collecting space comprising an area of knurling, there being passage means from said collecting space to said push rod receiving seat.

3. For use in a hydraulic lash adjuster, a hollow plunger open at one end and having a push rod receiving magma seat at its other end, said plunger shaped on its exterior to provide a reservoir space comprising an area of knurling and having a passage from said reservoir space to its interior, said plunger also being provided with a lubricantcollecting space on its exterior, said collecting space comprising an area of knurling, there being passage means from said collecting space to said push rod receiving seat, and a metering pin positioned within said passage means.

4. For use in a hydraulic lash adjuster, a hollow plunger open at one end and having a push rod receiving seat at its other end, said plunger shaped on its exterior to provide a reservoir space comprising an area of knurling and having a passage from said reservoir space to its interior, said plunger also being provided with a lubricantcollecting space on its exterior, said collecting space comprising an area of knurling, there being passage means from said collecting space to said push rod receiving seat, and a metering pin loosely positioned within said passage means.

5. In combination in a hydraulic lash adjuster, a cylinder having a closed end and an open end, a hollow plunger mounted therein, spring means within said cylinder and in contact with its closed end and with the plunger and biased to move the plunger outwardly with respect to the cylinder, said plunger having upon its exterior a reservoir space comprising an area of knurling, and a passage extending from said reservoir space to the interior of said plunger, said plunger having a lubricantcollecting means on its exterior, said collecting means including an area of knurling, said plunger having on its outer end means defi ing a push rod receiving portion, there being passage means extending from said receiving portion to said lubricant-collecting means, and a metering pin loosely positioned in said passage means.

6. In combination in a hydraulic lash adjuster, a cylinder having a closed end and an open end, a hollow plunger mounted therein, spring means within said cylinder and in contact with its closed end and with the plunger and biased to move the plunger outwardly with respect to the cylinder, said plunger having upon its exterior a reservoir space comprising an area of knurling, and a passage extending from said reservoir space to the interior of said plunger, said plunger having a lubricantcollecting means on its exterior adjacent its upper end, said collecting means including an area of knurling, said plunger having on its outer end means defining a push rod receiving portion, there being passage means extending from said receiving portion to said lubricant-collecting means.

7. In combination in a hydraulic lash adjuster, a cylinder having a closed end and an open end, a hollow plunger mounted therein, spring means within said cylinder and in contact with its closed end and with the plunger and biased to move the plunger outwardly with respect to the cylinder, said plunger having upon its exterior a reservoir space comprising an area of knurling, and a passage extending from said reservoir space to the interior of said plunger, said plunger having a lubricantcollecting means on its exterior adjacent its upper end, said collecting means including an area of knurling, said plunger having on its outer end means defining a push rod receiving portion, there being passage means extending from said receiving portion to said lubricant-collecting means, and a metering pin loosely positioned in said passage means.

8. In combination in a hydraulic lash adjuster, a cylinder having a closed end and an open end, a hollow plunger mounted in said cylinder for reciprocation, means to retain said plunger in said cylinder, means positioned between the plunger and the closed end of the cylinder and biased to move the plunger outwardly, said plunger having an open end, a valve positioned to close said open end, a valve retainer mounted on the plunger and about the valve, a spring bearing upon said valve and biased to seat said valve, means defining a reservoir space about the exterior of said plunger, said means comprising a band of knurling extending about the exterior of said plunger, a passage connecting said reservoir space with the interior of said plunger, said plunger shaped to provide a receiving socket for a push rod in its upper end, a band of knurling positioned about the exterior of said plunger, and passage means extending from said socket to said band of knurling.

9. In combination in a hydraulic lash adjuster, a cylinder having a closed end and an open end, a hollow plunger mounted in said cylinder for reciprocation, means to retain said plunger in said cylinder, means positioned between the plunger and the closed end of the cylinder and biased to move the plunger outwardly, said plunger having an open end, a valve positioned to close said open end, a valve retainer mounted on the plunger and about the valve, a spring bearing upon said valve and biased to seat said valve, means defining a reservoir space about the exterior of said plunger, said means comprising a band of knurling extending about the exterior of said plunger, a passage connecting said reservoir space with the interior of said plunger, said plunger shaped to provide a receiving socket for a push rod in its upper end, a band of knurling positioned about the exterior of said plunger adjacent its upper end, and passage means extending from said socket to said band of knurling.

10. In combination in a hydraulic lash adjuster, a cylinder having a closed end and an open end, a hollow plunger mounted in said cylinder for reciprocation, means to retain said plunger in said cylinder, means positioned between the plunger and the closed end of the cylinder and biased to move the plunger outwardly, said plunger having an open end, a valve positioned to close said open end, a valve retainer mounted on the plunger and about the valve, a spring bearing upon said valve and biased to seat said valve, means defining a reservoir space about the exterior of said plunger, said means comprising a band of knurling extending about the exterior of said plunger, a passage connecting said reservoir space with the interior of said plunger, said plunger shaped to provide a receiving socket for a push rod in its upper end, a band of knurling positioned about the exterior of said plunger adjacent its upper end, passage means extending from said socket to said band of knurling, and a metering pin loosely positioned within said passage means.

11. For use in a hydraulic lash adjuster, a hollow plunger open at one end and having a push rod receiving seat at its other end, said plunger shaped on its exterior to provide a reservoir space comprising an area of knurling and having a passage from said reservoir space to its interior, said plunger also being provided with a lubricantcollecting space on its exterior, said collecting space comprising an area of knurling, there being passage means from said collecting space to said push rod receiving seat, and metering means positioned to control and to meter fluid passing through said passage means.

12. In combination in a hydraulic lash adjuster, a cylinder having a closed end and an open end, a hollow plunger mounted in said cylinder for reciprocation, means to retain said plunger in said cylinder, means positioned between the plunger and the closed end of the cylinder and biased to move the plunger outwardly, said plunger having an open end, a valve positioned to close said open end, a valve retainer mounted on the plunger and about the valve, a spring bearing upon said valve and biased to seat said valve, means defining a reservoir space about the exterior of said plunger, said means comprising a band of knurling extending about the exterior of said plunger, a passage connecting said reservoir space with the interior of said plunger, said plunger shaped to provide a receiving socket for a push rod in its upper end, a band of knurling positioned about the exterior of said plunger adjacent its upper end, passage means extending from said socket to said band of knurling, and metering means positioned to control and to meter fluid passing through said passage means.

5 6 13. In an hydraulic tappet, a hollow cylinder closed References Cited in the file of this patent at one end, a hollow plunger mounted in said cylinder UNITED STATES PATENTS for reciprocation, a check valve mounted at the lnner end of said plunger cooperating to form a compression 2,163,969 Whalen June 1939 space between the inner end of said plunger and the 5 2,865,352 Thompson 1958 closed end of said cylinder, a passage through the wall 2,874,685 Llne 1959 of said cylinder, an area of knurling on the outer surface 2,964,027 Dadd 1960 of said plunger in communication With said passage, a passage through the wall of the plunger from said knurl- FOREIGN PATENTS ing to the interior of said plunger to admit fluid to the 10 1,098,609 France Mar. 9, 1955 interior of said plunger. 925,866 Germany Mar. 31, 1955 

9. IN COMBINATION IN A HYDRAULIC LASH ADJUSTER, A CYLINDER HAVING A CLOSED END AND AN OPEN END, A HOLLOW PLUNGER MOUNTED IN SAID CYLINDER FOR RECIPROCATION, MEANS TO RETAIN SAID PLUNGER IN SAID CYLINDER, MEANS POSITIONED BETWEEN THE PLUNGER AND THE CLOSED END OF THE CYLINDER AND BIASED TO MOVE THE PLUNGER OUTWARDLY, SAID PLUNGER HAVING AN OPEN END, A VALVE POSITIONED TO CLOSE SAID OPEN END, A VALVE RETAINER MOUNTED ON THE PLUNGER AND ABOUT THE VALVE, A SPRING BEARING UPON SAID VALVE AND BIASED TO SEAT SAID VALVE, MEANS DEFINING A RESERVOIR SPACE ABOUT THE EXTERIOR OF SAID PLUNGER, SAID MEANS COMPRISING A BAND OF KNURLING EXTENDING ABOUT THE EXTERIOR OF SAID PLUNGER, A PASSAGE CONNECTING SAID RESERVOIR SPACE WITH THE INTERIOR OF SAID PLUNGER, SAID PLUNGER SHAPED TO PROVIDE A RECEIVING SOCKET FOR A PUSH ROD IN ITS UPPER END, A BAND OF KNURLING POSITIONED ABOUT THE EXTERIOR OF SAID PLUNGER ADJACENT ITS UPPER END, AND PASSAGE MEANS EXTENDING FROM SAID SOCKET TO SAID BAND OF KNURLING. 